21841031 has 4 divisors (see below), whose sum is σ = 22594200. Its totient is φ = 21087864.

The previous prime is 21841021. The next prime is 21841037. The reversal of 21841031 is 13014812.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21841031 is a prime.

It is a super-2 number, since 2×21841031² = 954061270285922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21840994 and 21841012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21841037) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 376541 + ... + 376598.

It is an arithmetic number, because the mean of its divisors is an integer number (5648550).

Almost surely, 2^21841031 is an apocalyptic number.

21841031 is a deficient number, since it is larger than the sum of its proper divisors (753169).

21841031 is an equidigital number, since it uses as much as digits as its factorization.

21841031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 753168.

The product of its (nonzero) digits is 192, while the sum is 20.

The square root of 21841031 is about 4673.4388837343. The cubic root of 21841031 is about 279.5273957805.

Adding to 21841031 its reverse (13014812), we get a palindrome (34855843).

The spelling of 21841031 in words is "twenty-one million, eight hundred forty-one thousand, thirty-one".